Wastewater has heretofore been processed by biological treatment within one or more bioreactor settling tanks, induced by aeration to allow bacteria to metabolize soluble organic contaminants within the wastewater. The bacteria in the wastewater are then allowed to settle downstream and be partially recycled to maintain the concentration of bioreactive bacteria for retreatment. Membrane filtration systems for biological treatment of wastewater are also generally known.
The foregoing referred to type of prior known bioreactor and membrane filtration systems for processing wastewater, involved frequent disassembly of equipment and interruptions in operation for replacement of parts and/or cleaning of the filtration membranes because of fouling thereof. Also, relatively large tank sizes and equipment installational space was required at increased costs in order to handle wastewater processing of given quantities so as to meet certain needs such as those on-board sea vessels dependent on the availability of vessel crew handling personnel.
It is therefore an important object of the present invention to provide a membrane filtration type of bioreactor system through which tank size, membrane fouling and installational space and size are reduced, as well as associated costs while accommodating certain wastewater processing needs.